Heat-resistant yarn and heat-resistant cord and process for making same



Patented Dec. 21, 1937 uNirsofsTATES .fHEhT-RE SISTAN T YA N; m nna'r-nsi, L j .1 SISTANT coup rm rnocsss tron 1 me sans x h, Eugene CiGwaltney and Leon A. Mn; 1 I 7' and Russell B. Newton, Columbus, G$., 8SfllIlI- ors to Bibb Manufacturing company. Macon;

Serial No. 43,454 i v No Drawing. Application October i Qz z'caim w n-:4)

1: this yarn and cord.

' It is well known in this 'art'that heat acts lll juriously upon cotton products; and, therefore,

injures all goods made of cotton when" the temperatures involved in their use become-excessive. i Automobile tires, for example, are practically made entirely of rubber and a highly specialized cotton cord, and offer anexample' of the in. jurious effects of heat upon go ods of this charac ter. It is generally agreed in the tire industry that the chief cause of failure in automobile tires is the' heat developed by internal resistance to the flexing strainsthe cords undergo in service; and that this heat is sumciently great to extract the moisture from the'textilefabric of the tires.

It is well known that' cotton yarn or cotton cord, as heretofore produced, when bone dry,

loses around from to40% oi itsjten'sile strength as compared ,with its; strength when containing its normal amount of moisture. It is the main object 01' thejpresent invention to produce a cotton cord'a'nd-other cottonproducts which maintainand retain their tensile strength substantially constant throughout all ranges of temperature to which they'm'ay-be'subjected in v ce, v h

-' The normal moisture content ofcotton cords heretofore employed in the manufacture of .tires and belting (used as a basis for testing the same) is about 6.5% by weight of the cord. It has 40 been found experimentally that for each decrease 01' 1% in the moisture content, the tensile strength of the cord is decreased about 6%. In

cords produced by petitioners process, the tensile strength is maintained substantially constant throughout all decreases of moisture content from normal to bone-dry; and in some cases has been actually increased.- This remarkable result has been obtained by thorough saturation of the fibres which make up the cotton yarns and cords;

5 and by subjecting the saturated yarns to steps of twisting under tension; compressing and stretching, as hereinafter described It is well known. in; the cotton industry that raw cotton contains normally "about 9% of moisture; and that the retention of approximateiy thisamounti'oi-moisturen the cotton is essential to the success of even normal processes of manufacturing" cotton into its" various textile products. In the course of converting cotton into various'types' of textiles,'-'the '-heat generated by 5 the friction of "the"machinery in the mill would cause a.- deteriorationin the tensile. strength oi the cotton products by'the removal of moisture therefrom, and would 'lriinderj'the successful processing of cotton inthe various textilelprod 1o ucts.' Toovercome this condition} cotton mills are equipped" with" means forartiilclally moistening theatmosphere thereofatomaintain lathe cottonfibre, the moisture "content-necessary to I in'sure'the tensil strength'and'proper' processing 15 w h .of' the cotton throughout it's-manufacture n the I r a gw l kn i f lt l w mo moisture"' injected into the f cotton "addsto its ns e r au1 PM th ma e: me 2:, which can injected artificially 10 otherwise into the cotton during the'processin g thereolf. is l m ed ba h in i fl c i isf v i e moisture has-outheyarious processesbf'conveib s i tt n m y m i woven fabrics; The[additionalamount of mois' ture is further limited by the iacti that excessi f moisture in; cotton products will;}' in a -short time, produce mildew] and rot. and thus destroy the tensile strength andwearlng Qualities oi! the cotton and-oi any productintowhlch it" may be made. Moreover, the buyers of cotton textiles object'to pin'chasing these textiles whentheyv contain more than a normal amount of moisture; Y, certainly 'no more than was in jtne "raw cotton as first introduced inthe mill. 1

In themanui'acture of the'heath and heat-rosistantjcord forming the subject matter of the present invention, it isdesirable accomplish two things with; respect to the cotton 40 andthe products manutactured therefrom: '1. The greatestj amount if moisture possil')le,-

consistent with'properprocessing,must be intro duced into thecotton while it is being processed: and V The efle'cto! increiiis nfl t e tensile strength of cott'on by the introduction'ot thejextra moisture must retained in thennishediproduct, without the retention in thatiinished prod exceedingethe moisture' content for the raw cot tonas it entered the mill, wmcii sthe moist re content a customer 'n'aturally" and flnds acceptable. 1

*In our eflortstoproducea 35 t of more than the "normal amount of moi'sture -hot would maintain its tensile strength substantially constant throughout the various temperature ranges to which it may be subjected we discovered that when yarn spun ofcotton. processed throughout the mill-in the normal way was saturated, twisted, stretched and compressed, we obtained a result in the finished yarn or'in'the finished cord having the following desirable characte'ristics: W

1. The finished goods contain nomore than the normal moisture content, which would be insufilcient-i'n amount to effect mildewing or rotting of the product;

2. .In saturating yarn with-moisture, the gum and-oils inherent inthe cotton fibre are softened,

when a number of these saturated yarns are twisted and pliedunder tension and are stretched and compressed the fibres adhere more closely to each other than is the case with cotton goods manufactured without the preliminary saturation, and the resultant yarnretains its tensile strength substantially constant throughout all changes of temperature to which it would be subjected in service.- n

3. Likewise when a number of the twisted saturated yarns are again twisted and compressed unQer tension into a cord and are stretched after the compressing the resulting cord retains its tensile strength substantially throughout all changes of temperature to which it would be subjected-in service.

We found that we could saturate the single yarn before twisting it intoplied' yarn where the plied yarn was to be the finished product, or that wherethe plied yarn was to be twisted into cord we could saturate the plied yjarn before twisting it. We found that the twisting could be done in the-usual manner or under tension or stretch as -compressin. We found that the compressing could be applied either to the plied yarn or, if the plied yarn wasto be manufactured into cord,

.to the cord} manufactured therefrom. We found also that thesaturating and twistingprocesses increased the herit-resistant qualities of the yarn,

and that such heat-resistant lqualities were fur'- ther increased when the tensionor, stretching process was used in additionjto the saturating and twisting, and that the compressing process further increased suclrheat-resistant qualities.

In carrying out the processinvolved in the production o'fthe heat-resistant cotton yarn or cord, the yarns are not merely wet; they are saturated. By saturated we mean that elemental cotton fibres have absorbed or taken. up liquid to'such an extent that the internal stresses or strains. of the fibers become, or approach; zero, and the gums or waxes which inhere on or in the fibres are softened; in other words, that thesubstance of the fibre no longer has to contend with internal stresses but is free to oppose resistance to stresses arising from the outside, and that the fibres and gums or waxes are thus fused ,to a greater extent than has heretofore obtained in the manufacture of yarns or. cord. In other words, the fibres become setand are bonded with the naturalgums and waxes.

When we state that, the saturated cottonyarn is twisted we mean that said yarn may be twisted in the usual manner or may be twisted under greater than normal tension or, stretch. When we refer to tension or "stretch" we mean that the saturated yarn is subjected to a greater tension .or stretch than is applied in the usual twisting operation, so that the elemental fibres are brought into closer contact, one with the other and are more closely bonded into a unified product than is caused by saturating and twisting alone. The higher'the'tension or stretch which is applied the higher is the heat-resistant quality. By compression we-mean compression by the usual means employed in the industry to reduce the diameter of a plied yarn or cord.

To recapitulate; the steps of the process producing our heat-resistant yarn" or cord vcomprise:

1. A complete liquid saturation of yarns, either single yarns or plied yarns;

2. A twisting of any desired number of the saturated yarns, which maybe done in the usual manner or under tension; g 3 3. A cabling or twisting of any desired number of the previously twisted, saturated yarns to produce a cord or cable, and drawing the same, under tension,.through a nipper or other device for cornpressing; and i 4. Stretching the cabled, twisted yarn to produce the finished cotton cord. I

Where cablingis not desired the steps of the process producing our heat-resistant yarn or cord comprise:

1 A complete liquid saturation of single yarns 2. A twisting of any desired number of the saturated yarns in the usual manner or under. tensionandif twisted in the'usual manner, subsequentlystretching the yarns and compressing the same'by drawing. under tensionthrough a nipper or otherfdevicefor compressing.

'The. stretching and'compressing may be carried out in anyorder; but the process consists of. the saturation of the, cotton yarn to soften the natural. gurn thereofiand'thereby permitting a. closer packingof the fibresitogether-and bonding with the natural gum during the various stepsof twisting, compressing and stretching. In the cord produced bythis processwe have found that while the'saturatio'n andtwisting increases the hone dry strength of-the cord, the additional stretching increasesit still further; and, when thestretched cord is compressed, the strength is still further increased. The comparative strengths under these difierent conditions, are set forth in the following table, which averages the results obtained by extensive tests in the laboratory of the assignee of this invention.

average of laboratory tests Size 1.0% 1. 074 1. 090 Gfllllfl 33. 25 32. 25 32. 00 Break. normal moisture. l v 20. 70 21. 65 22.10 Stretch at 10! 6. 83 3. 86 3. 72 Stretch at break 11.96 9.60 9. 05 Bone-dry break..-" 20.08 21.43 22.85 Stretch at 101... 6. M 5. 25 5. O8 Stretch at break 7 10. 10 8. 50 8. 50

#L-Regular heat resistantsaturated only. ail-Saturated and stretched. flat-Saturated, stretched and compressed. It will be apparent fromthis table that where the yarns are saturated only, the bone-dry break is slightly less than-the break at normal moisture content; and that the stretch at bone-dry break is also less than at normal moisture content break. The same condition holds substantially when the cord is stretched in additionto being saturated. When the yarns are saturated, twisted, stretched and compressed, test #3 actually shows an increase in bone-dry break over the break at normal moisture content, and shows adecrease in stretch at boneedry break. I i

yarns and cord'are apparent, when it is considered in connection with the established fact that the tensile strength in yarn and'cords produced by prior processes decreasesca matter of about 6% 'for every 1% decrease in'moisture'content from the normal moisture"ccntent for-testing of about 6.5%. As a result of this discovery, we are able, by the process described, to produce a yarn, twine, cord, or other fabric composed of cotton fibres and cotton yarn' that will resist the deteriorating and destroying effects of high temperature; which products'can be incorporated in various articles of manufacture designed for use under conditions where high temperatures are either "produced in the normal conditions of use of the articles, or where the product is to be used under conditions-subjecting it to high temperatures. As aresult, it is evident that such articles will have a longer life of usefulness than has been previously obtained by any known process of manufacturing cotton fibres into such products and articles. r

In the specification and in the claims of this case, the word yarn or yarns means any single yarn or any plied yarn composed of any number of single yarns plied or folded together;

and the word cord means any number of plied yarns twisted into a cord or cable.

What we claim is:

1. The process of manufacturing heat resistant cotton cord which consists in twisting single cotton yarns into a ply, saturating the plied yarns to soften the natural gums and waxes of the cotton fiber, and twisting while wet the saturated plied yarnsunder tension just short of breaking point to fuse the fibers with waxes retained therein.

2. The process of manufacturing heat resistant cotton cord which consists in twisting single cotton yarns into 9. ply, saturating the plied yarns to soften the natural gums and waxes of the cotton fiber, twisting the saturated plied yarns under tension just short of breaking point to fuse the fibers with the softened gums and waxes retained therein, and compressing the cord resulting from the saturation, twisting and stretching of the pliedyarns.

V 3. A heat resistant cotton yarn in which the cotton fibers are compacted by twisting and stretching while the natural gums and waxes of the fibers are softened by saturation, and have.

ing substantially constant tensile strength during all changes of moisture content from nor- This stretch was determined by subthe softenend gums and mal to bone dry, and having a substantially lower stretch anddianieter than normally processed cotton yarn containingthe same quantity of cotton per unit length; e I

4. A heat resistant cotton cord in which the cotton fibers. are compacted by twisting and stretching "while tlge natural gums and waxes of the fibers are softened by saturation, and having substantially. constant tensile strength" during. all changesof moisturecontent from normalto bone dry, and having a substantially lower stretch and diameter-than-pormally processed cotton cord containing the :same quantity of cotton-perunitlength,

5:..The process of manufacturing a heat-resistantcotton yarn or cord, which consists .in

saturating cotton .yarns with non'-cotton-de-- stroying and non-coating liquid, twisting-the wet saturated yarns, and stretching-the wet twisted ingpoint. w The process of manufacturing av heat-resistant cotton yarn or cord, which consists/in saturating cotton yarns, with non-cotton-destroyingand non-coating liqui'd, and twisting the wet saturated yarns under tension just short of the breakingpoint;

7. The process of manufacturing a heat-resistant cotton 'yarn'orcord, which consists in saturating cotton yarns: with .non-cotton-deyarns or cord under tensionjust short of break .stroying and non-coatingliquid,xtwisting the'wet saturated yarns-stretching the wettwisted yarns under tension justshort'of thebreaking point,

and compressing said stretched yarns or cords; 8. The process of manufacturing-a heat-resistant cotton-yarn'or-cord, which consists in saturating cotton yarns with non-cotton-destroying' and non-coating liquid, twisting the wet saturated yarns under tension just'short of the breakingpoint, and compressing said twisted and tensioned yarns or'cord; 9. The p'rocess'of manufacturing a heat-resistant cotton yarnor cord, which consists in twistingthe single yarns into'a ply, saturating the'plied yarns with a non-cotton-destroying and non-coating liquid, cabling said wet plied yarns to form a cord, and stretching said cord under tension just short of the breaking point.

10. The process of manufacturing a heat-resistant cotton yarn or cord, which consists in twisting the single yarns into a ply, saturating the plied yarns with a non-cotton-destroylng and non-coating liquid, and cabling the wet plied yarns under tension just short of the breaking point.

' 11. The process of ,manufacturing aheat-resistant cotton yarn or cord, which consists in twisting the single yarns into a ply, saturating the plied yarns with a non-cotton-destroying and non-coating liquid, cabling said wet plied yarns to form a cord, stretching thewet cabled cord under tension, just short of the breaking point, and compressing said stretched cord.-

' 12. The process of manufacturing a heat-resistant cotton yarn or cord, which consists in twisting the single yarns into a ply, saturating the plied yarns with a non-cotton-destroying and non-coating liquid, cabling said wet plied yarns under tension just short of the breakingpoint to form a cord, and compressing said cord.

13. The process of manufacturing a heat-re sistant cotton cord which consists in twisting single yarns of cotton to form plied yarns, saturating the plied yarns with non-cotton-destroying and non-coating liquid, twisting the wet plied yarns toform-a cord, and stretching the plied yarns during thetwisting thereof under tension just below breaking point; a

14. The process of manufacturing aheat-resistant' cotton cord which consists in twisting single yarns of cotton to form plied yarns-saturating the plied yarns with non-cotton-destroying-and non-coating liquid, twisting the plied yarns to form a cord, stretching the plied yarns during theztwisting thereof .under tension just below breaking point, and compressing the twisted and stretched cord. a

15. A heat resistant cotton. yarn, the natural gums and waxes of which have been softened and rehardened and having substantially constant tensile strength; during alli changes'of moisture content from normal to bone dry, and having substantially lower stretch'anddiameter than normally-processed cotton yarn containing the samequantity of cotton per unit length.

16. A heat resistant cotton cord, thenaturai gums and waxes ofwhich have beensoftened and rehardened, and having substantially. constant tensile strength duringallchanges of moisture.

content from normal to bone dry,vand=,ha ving substantially lower stretch and diameter than normally processed cottonlcordcontaining the samequantity of cotton per unit'length. 17. A heat resistantcotton yarn; the natural gums and waxes ofwhich have been softened by saturation and rehardened,land having substantially constant tensile strength during. all changes of moisture content from normal tovbone dry, and having substantially lower, stretch anddiameter than normally processed cotton yarn containing the same quantity of cottonper unit length. i I

18. .A heat resistant cotton cord, the-natural gums and waxes of which have been softened by saturation and rehardened, and having-substantially constant tensile strength during all changes of moisture content from normal to bone dry, and having substantially lower. stretch and diameter than normally processed cotton cord containing the same quantity; of cotton per unit lengthr v a a 1 1 r.

soften the ndtural gums and waxes thereof;

stretching the saturated yarns, threads, cords and the like substantially tothe breaking point while the said gums and-waxes are softened, to place the individual elementscomposing said yarns, threads, cord or the like under substantially uniform tension; and permanently setting the yarn, thread, or cord or the like ina'stretchedconditionby hardeningthe natural gums and waxes around the individual yarns and flber. V 21. The; process of manufacturing heat resistant cotton yarns, threads, cords and the like which consists in saturating said yarns, threads,

cords and the like to soften the natural gums and waxes thereof; and twisting said saturated yarns, threads, .cords and the like,-,while the said gums andwaxesare softened, under tension just short of the :breaking'point, to fuse the cotton fibers with the'softenedgums and waxes retained therein. :1 l I I 22. Theprocessof manufacturing heat, resistant cotton yarns, threads, .cords and the like which-consists in saturating saidyarns, threads, cords and the like to soften the natural gums and waxes thereofrand twisting said saturated yarns, threads, cords and the like, while the said gums and'waxes are softened, under tension just short of the breaking point, to fuse the cotton fibers with -'the softened gums and waxes retained therein and compressingthe threads or cords resulting from the saturation and twisting under tension of said saturated yarns, threads, cords and thelikeiw a I EUGENE C. GWALTNEY, LEON A. GRAYBILL'.

RUSSELL B. NEWTON. 

